A semiconductor device proposed in the related art (for example, see Patent Literature 1) has an element portion and a sealing portion surrounding the element portion, and a sealing structure surrounding the element portion is formed in the sealing portion. More specifically, the semiconductor device has a substrate, and a laminated wiring layer unit formed by alternately laminating interlayer insulating films and wiring layers is disposed on the substrate. In the sealing portion, the wiring layers in the respective layers are formed in frame shape and connected to one another so as to surround the element portion.
A nitride film having lower permeability to moisture (water drops and water vapor) than the interlayer insulating film is provided on the laminated wiring layer unit. That is to say, the nitride film restricting moisture from coming inside the laminated wiring layer unit from outside is provided on the laminated wiring layer unit. The nitride film is provided with a via-hole, through which an uppermost wiring layer located at a top of the laminated wiring layer unit and nearest to the nitride film is exposed, and a sealing layer is provided in the via-hole.
The via-hole is formed in a frame shape along the uppermost wiring layer and the sealing layer is therefore also formed in a frame shape. Hence, the wiring layers and the sealing layer in the laminated wiring layer unit together form the sealing structure surrounding the element portion.
The semiconductor device as above is manufactured as follows. That is, a semiconductor wafer is prepared first. The semiconductor wafer includes multiple chip regions each having the element portion and the sealing portion and the respective chip regions are defined by scribe portions. The laminated wiring layer unit is provided on the semiconductor wafer and the nitride film is provided on the laminated wiring layer unit. Subsequently, the sealing structure to surround the element portion is formed by providing the via-hole to the nitride film and providing the sealing layer. The semiconductor device is manufactured by dicing the semiconductor wafer into individual chips along the scribe portions using a dicing cutter or the like.
According to the manufacturing method as above, although cracking (chipping) may occur in an outer edge of a chip (semiconductor device) in some cases when the semiconductor wafer is diced into individual chips, the sealing structure restricts the cracking from extending. Hence, propagation of the cracking to the element portion can be restricted.
In the semiconductor device manufactured as above, however, the nitride film having low adhesion to metal (sealing layer) is exposed and the nitride film readily peels. Hence, in the semiconductor device manufactured as above, the nitride film may possibly peel and become a foreign substance during transportation of the semiconductor device or during use of the semiconductor device. In particular, in a case where cracking occurs in the nitride film when the semiconductor wafer is diced, the nitride film peels more readily due to the cracking.